The exemplary embodiment relates to systems and methods for transmitting and receiving messages and in particular to a system for providing a textual representation of an audio message to a mobile device.
Mobile devices for transmitting and receiving voice communications, such as cell phones are now in widespread use. During meetings and at certain events such as stage and concert events, it is often unacceptable to allow a cell phone to ring. Accordingly, cell phones have been adapted to provide a silent mode which allows a recipient to see that a call has been received. However, the recipient must then leave the meeting or other event to listen to the call or wait until later to retrieve a voice message that the caller has recorded. Neither of these options is entirely satisfactory. Often, users switch their phones off entirely to avoid facing the difficult decision of whether to interrupt a meeting.
Speech recognition systems have been developed which are able to convert voice to text. A standard approach converts speech waveforms into a digital signal split then into pieces of data. The data, comprising sequences of symbols, are then aligned with lexicon entries using search algorithms such as the Viterbi algorithm and disambiguated using, for example, Hidden Markov Models (HMM). For accurate recognition, an extensive lexicon is accessed which allows the detected sounds to be matched with words in the language of the speaker. Such systems thus incorporate substantial memory power and are generally most effective when the system can be trained to the voice of the speaker.
In the case of cell phones, the desire is to maintain a portable and lightweight device which is essentially disposable. Operating systems which have a large memory requirement or which contribute to significant battery consumption are therefore undesirable. Cell phone users have the opportunity to send and receive text messages to generate of the type currently called SMS, an acronym for Short Message Service. An advantage of SMS is that the content of a message is directly sent to a user's cell phone. There is no need to connect to a remote messaging server to access the message. It does not require any vocal component, and it is a relatively unobtrusive operation to read a short text on a cell phone. However, the conventional keypad on mobile devices is quite small and inconvenient to use. Callers who are unable to make contact with the cell phone user often prefer to rely on the recipient retrieving a voice message.